Method of making rivets.



D. G. CLARK. BEST AVAILABLE COPX mmnon or MAKING RIVETS.

APPLIOATXOR FILED MALES. 1910.

970,687. Patented Sept. 20, 1910.

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D. G. CLARK.

METHOD OF MAKING RIVETS.

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970,687. Patented Sept. 20, 1910.

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WITNESSES:

UNITED STATES PATENT OFFICE.

DWIGHT G. CLARK, OF PLAINVILLE, CONNECTICUT, ASSIGNOR TO EAGLE LOCK (30., 0F TERRYVILLE, CONNECTICUT, A CORPORATION OF CONNECTICUT.

METHOD OF MAKING RIVETS.

Specification of Letters Patent.

Patented Sept. 20, 1910.

Original application filed September 9, 1909, Serial No. 516,839. Divided and this application filed March 28, 1910. Serial No. 551,976.

To all whom it may concern:

Be it known that I, DWIGHT Gr. CLARK, a citizen of the United States, residing at Plainville, in the county of Hartford and State of Connecticut, have invented certain new and useful Improvements in Methods of Making Rivets, of which the following is a specification.

My invention relates to an improved method of manufacturing rivets and this application is a division from #516,839 filed Sept. 9th, 1909 in which I claim the mechanism herein illustrated.

One object is to produce a rivet having a full round or oval head.

Another object is to produce a special form of rivet economically and yet so that it will have great strength. The preferred rivet is bifurcated at one end and has a recess extending beyond the bottom of the notch.

The new complete method in its preferred form comprises cutting off the end of the wire or rod stock so as to form a blank, wedge-shaped at one end and notched or bifurcated at the other end, then indenting the notched end and heading the wedgeshaped end of the blank. This can be carried out very simply in an ordinary rivet machine or header by employing V-shapcd cutters in place of the common straight cutoff tools and a tapered or pointed knock-out pin or abutment in place of theusual flatended one. It will therefore be unnecessary to illustrate a complete machine.

The accompanying drawings show the necessary tools and some modifications for carrying out the method.

Figure 1 is a plan View and horizontal section of the tools for a solid die header showing the parts in position to cut off the stock and form a blank, the forming dies being shown in full. Fig. 2, is a plan view and horizontal section of the same parts, the blank being severed and transferred to the forming dies which are shown in section, the stationary cutter being shown in plan. Fig. 3, is a plan view and horizontal section of the same tools showing the rivet formed and the movable cutter in position permitting the feeding of the stock. Fi 4, is a side View of the severed blank. Fig. 5, is a perspective view of a completed rivet. Fig. 6, is a side view of the stationary cutter. Fig. 7, is an end view of the same. Fig. 8, is a rear view of the movable cutter. Fig. 9, is a section of the same on the line X--X of Fig. 8 looking upward. Fig. 10, is a side view of the pointed pin serving as an abutment and knock-out. Fig. 11, is a horizontal section of tools for an open die header the position of the parts corresponding with those in Fig. 1. Fig. 12, is a. horizontal section of the same, the blank being severed and in position for forming. Fig. 13, is a side view and vertical section of the stationary and movable cutters respectively of Figs. 11 and 12. Fig. 14:, is an end View of the movable cutters of Figs. 11, 12 and 13. Fig. 15, is a horizontal section of a modification of the tools of Figs. 11 to 13.

In the form of solid die header used for this method the cutters consist of the stationary tube or block 1 and the intermittently movable slide 2. The stock 3 is fed intermittently through the holder 4 and block 1 as usual. The outer end of the block 1 is provided with a wed e-shaped projection 5 affording a cutting e go 6 angular in cross section (see Figs. 6 and 7). The slide 2 has a groove 7 of the same cross section affording a corresponding cutting edge 8 (see Figs. 8 and 9). The usual spring pressed gripping finger 9 may be employed (see Fig. 8) to assist in transferring the severed blank from the position of Fig. 1 to the position of Fig. 2. The slide is operated in the usual manner and cuts off the end of the stock to form blanks such as 10 which are thus wedge-shaped at the front end and grooved or notched at the rear end 12 (see Fig. 4).

The solid die 13 has a recess or passage 14 to receive the blank 10 and the hardened knock-out pin 15 which is tapered or pointed at the front end 16. The pin is operated as usual by an arm 17. A stop 18 may be provided. The blank 10 is carried oier' in front of the die recess 14 by the slide 2 and finger 9. The header 19 is carried by its holder or slide 20 and has a heading recess and is operated in the ordinary manner. The header 19 pushes the blank 10 into the die recess 14 and forces the end 12 against the pin point 16. The pin is thus pushed in until it strikes the arm 17 which is then stationary in the position of Fig. 2. The forcing of the blank onto the pin drives the point into the bottom of the notch or groove of the blank and, causing some of the metal in the center of the notch to flow slightly toward the ends, forms a conical recess 21 (see Fig. 5) in the end of the shank with the webs 22, 22 connecting the prongs 23, 23 and compresses the metal thus strengthening it. The continued movement (to the left in the drawings) upsets the wedgeshaped end 11 of the blank and forms the head 24 (see Fig. 2). The wedge-shaped end 11 of the blank swages up into a full round or oval headed rivet with much less pressure than is required by ordinary processes. The head may be made of other shapes, however if desired, so far as the other features of the invention are concerned by using a header with the proper recess. The solid die prevents the prongs 23, 23 from spreading when driven onto the abutment point 16.

In using the open die form of mecha nism shown in Figs. 11 to 14 the stock 25 is fed through the block 26 which has a wedgeshaped projection 27 whose edges, where the stock extends to the right, form a cutting edge. The cutter block 28 has a groove 29 with a cutting edge at 30. Block 31 in conjunction with block 28 serves to hold the blank 32 as it is being cut off and they transfer it over in front of the pointed pin 33. The header 34 then drives the blank on to the point of the pin 33 (see Fig. 12) to form the recess in the grooved or notched end of the blank. The blocks 28 and 31 hold the blank as the header 34 upsets the outer end of the blank to form the head of the rivet (not shown). The pin 33 may be operated by the arm 35 to knock-out the finished rivet if desired. The blocks 28 and 31 are usu ally made alike and each is reversible for purposes of economy.

Instead of using a knock-out pin, the pointed abutment 36 may be stationary as shown in Fig. 15, the point being in line with the groove 37 of the dies 38 and 39. When the dies are separated the finished rivet 40 will fall out or may be blown or knocked out in any suitable manner.

This method as performed results in a rivet having prongs at one end connected at the sides by shallow webs which when the rivet is used produce a head, round or slightly oval in end view having great strength and holding power.

The angles of the cutting edges 6 and 8 may be 90 more or less so as to produce greater or lesser up-setting portions in the blank. The length of the wedge 11 is practically the same as the depth of the notch 12 allowing for the slight drawing action of the cutters in ordinary commercial operation. This dimension I prefer should be less than the diameter of the stock in order to prevent any possibility of deflection or curling in the upsetting action. The angle of the abutment 16 is preferably the same as or slightly less than the angle of the notch 12. The pin 15 need not come to an exact point and in fact if pointed at the start will soon wear off slightly. It is sufiicient if the end be given a substantial taper so as to drive into the notch 12 and force some of the metal from near the center outwardly toward the ends of the notch and form a conical indentation. The tapered or wedge-shaped end 11 of the blank fills the rounded recess of the header much better than a square ended blank would do. The particular shape of the heading recess may however be made in accordance with the shape of the desired product.

lVhat I claim is l. The method of forming a rivet which comprises cutting a notch in a blank with inclined lateral walls, and then forcing some of the metal from the central portion of the notch to the ends of the notch.

2. The method of forming a rivet which comprises cutting a notch in a blank with inclined lateral walls, and then forcing some of the metal from the central portion of the notch to the ends of the notch and subsequently upsetting the opposite end of the blank.

3. The method of making rivets which comprises cuttin a blank wedge-shaped at one end and notched at the other end, indentlng the notched end and upsetting the wedge-shaped end.

4. The method of making rivets which comprises cutting a blank, notched at one end, driving the notched end against a tapered abutment to form a recess extending below the bottom of the notch and heading the other end while the notched and recessed end is against the tapered abutment.

5. The method of making rivets which comprises cutting a blank wedge-shaped at one end, the length of the wedge-shaped portion being less than the diameter of the stock, and then-upsetting the wedge-shaped end to form a round or oval head.

6. The method of making rivets which comprises forming a blank notched at one end and wedge-shaped at the other end, the depth of the notch being substantially equal to the length of the wedge and not substantially greater than the diameter of the stock, indenting the notched end and upsetting the wedge-shaped end to form a head.

7. The method of making rivets which comprises forming a blank notched at one end and wedge-shaped at the other end, the depth of the notch being substantially equal to the length of the wedge and not substantially greater than the diameter of the stock, end portion to form a blank notched at its and upsetting the Wedge-shaped end to form rear end, then indenting the notched end a head. and then upsettin the wedge-sha ed end.

8. The method of making rivets which 5 comprises cutting ofi the front end of a piece Witnesses:

of stock to leave the remainder Wedge- E. BRADFORD,

shaped on the end then severing the new Rom. S. ALLYN.

WIGHT G. LARK. 

